@phdthesis{Ren2022a,
  author = "J. Ren",
  title = "Characteristics and Generation Mechanism of Polar Cap Patch: Multi-instrument Observations",
  year =  2022 ,
  month = "May",
  keywords = "pfisr, risrn, risrc, dissertation, phdthesis",
  doi = "https://dx.doi.org/10.7302/4781",
  url = "https://hdl.handle.net/2027.42/172752",
  school = "University of Michigan"
}


@article{Zou2021a,
  author = "S. Zou and J. Ren and Z. Wang and H. Sun and Y. Chen",
  title = "Impact of Storm-Enhanced Density (SED) on Ion Upflow Fluxes During Geomagnetic Storm",
  year =  2021 ,
  journal = "Frontiers in Astronomy and Space Sciences",
  volume = 8,
  keywords = "pfisr",
  doi = "10.3389/fspas.2021.746429",
  url = "https://www.frontiersin.org/articles/10.3389/fspas.2021.746429"
}


@article{Ren2020b,
  author = "J. Ren and S. Zou and E. Kendall and A. Coster and K. Sterne and M. Ruohoniemi",
  title = "Direct Observations of a Polar Cap Patch Formation Associated With Dayside Reconnection Driven Fast Flow",
  year =  2020 ,
  journal = "Journal of Geophysical Research: Space Physics",
  volume = 125,
  number = 4,
  keywords = "sondre",
  doi = "https://doi.org/10.1029/2019JA027745",
  url = "https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019JA027745"
}


@article{Ren2020a,
  author = "J. Ren and S. Zou and J. Lu and N. Giertych and Y. Chen and R. H. Varney and A. S. Reimer",
  title = "Statistical Study of Ion Upflow and Downflow Observed by PFISR",
  year =  2020 ,
  journal = "Journal of Geophysical Research: Space Physics",
  volume = 125,
  number = 10,
  keywords = "pfisr",
  doi = "https://doi.org/10.1029/2020JA028179",
  url = "https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020JA028179"
}


@article{Ren2018a,
  author = "J. Ren and S. Zou and R. G. Gillies and E. Donovan and R. H. Varney",
  title = "Statistical characteristics of polar cap patches observed by RISR‐C",
  year =  2018 ,
  journal = "Journal of Geophysical Research: Space Physics",
  publisher = "American Geophysical Union",
  volume = 123,
  keywords = "risrc",
  doi = "10.1029/2018JA025621"
}